<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8" />
    <title>1.debugger的使用</title>
  </head>
  <body>
    <script type="text/javascript" >
      let arr = [{x:100},{y:200}]

      console.log(arr) // [{x:100},{y:200}]
      debugger;
      arr[0].x = 666
      console.log(arr)  // [{x:666},{y:200}]

    </script>
  </body>
</html>